1. Field of the Invention
The present invention relates to an information display apparatus which is incorporated in or connected to a video playback apparatus or video recorder/player apparatus represented by a television receiver, DVD apparatus, or hard disk video recorder and provides a closed caption display function, an information display method, and a program.
2. Description of the Related Art
Television broadcasts and DVD video contents provide closed caption information that supplements speech information. In a television broadcast, teletext signals are superposed on video signals. More specifically, character information is transmitted using an identification signal (VBI signal) inserted during a vertical blanking period (see, e.g., Japanese Patent Laid-Open No. 9-65295). DVDs and the like are so designed as to record multilingual closed caption information together with images and speech. Digital high-definition television broadcasts can also transmit closed captions as sub-video information.
The use of closed caption character information is effective not only for a hearing impaired person and deaf person but also for a normal listener when it is hard to hear speech corresponding to an image (for example, when the playback sound volume is small or ambient noise is large). This is also effective when it is difficult to play back speech corresponding to an image so as to be able to hear it (for example, in high speed playback such as fast-forward playback while displaying an image, slow-motion replay, pause, backward playback, or multi-screen display).
However, a conventional video playback apparatus or information display apparatus does not provide closed caption character information display functions corresponding to viewing situations. A technique of displaying a closed caption in a mute state has also been known (see, e.g., Japanese Patent Laid-Open No. 7-46500). No conventional video playback apparatus or information display apparatus provides a function of controlling display of closed caption character information in accordance with the viewing situation.
It is an object of the present invention to provide an information display apparatus capable of controlling display of closed caption character information in accordance with a viewing situation, and an information display method therefor. In playing back an image by a television receiver, video playback apparatus, video recorder/player apparatus, or the like, or playing back speech by a speech playback apparatus, speech recorder/player apparatus, or the like, closed caption character information is displayed or the display form is changed in accordance with the speech playback status to appropriately supplement speech information in, e.g., a situation in which it is probably impossible or hard to hear or understand speech.